Gemeinsam mit einem norwegischen Wissenschaftlerteam wurde ein statistisches Verfahren entwickelt, mit dem sich die zukünftigen Bestände des Kabeljaus in der Barentssee besser vorhersagen lassen. Diese neue Methode könnte das Fischerei-Management der Kabeljaubestände nachhaltig verbessern. Bedingt durch zahlreiche Einflüsse wie etwa den Klimawandel oder den Fischereidruck wird seit Jahren von Wissenschaft und Umweltverbänden vor einer Überfischung des Kabeljaus gewarnt. Mit dem Modell ist dem Forscherteam zum ersten Mal eine langfristige Prognose gelungen, die die Vorhersage des Bestandes für bis zu sieben Jahre im Voraus ermöglicht. Diese Prognosen sind bereits ab dem zweiten Jahr deutlich genauer als die ICES Vorhersagen. Bis 2024 prognostiziert das Rechenmodell eine fortschreitende Abnahme der Biomasse des Kabeljaubestandes in der Barentssee.
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Calculating the future of cod in the Barents Sea
Together with a Norwegian team of scientists, coastal researchers at Helmholtz-Zentrum Geesthacht have developed a statistical procedure that will help predict future cod stocks in the Barents Sea. This new method could sustainably improve cod fishery management. Due to numerous influences, such as climate change or fishing pressure, scientific and environmental organizations have been issuing warnings about overfishing for years. For the first time, the scientists have achieved a long-term forecast that will allow stock prediction for up to seven years in advance. These forecasts are already more accurate than the ICES forecasts from the second year onwards. The model developed by the scientists predicts a progressive decrease in cod biomass in the Barents Sea by 2024.
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Årthun, M., Bogstad, B., Daewel, U., Keenlyside, N.S., Sandø, A.B., Schrum, C., & Ottersen, G. (2018): Climate based multi-year predictions of the Barents Sea cod stock. PLoS ONE 13(10): e0206319, doi:10.1371/journal.pone.0206319
Abstract:
Predicting fish stock variations on interannual to decadal time scales is one of the major issues in fisheries science and management. Although the field of marine ecological predictions is still in its infancy, it is understood that a major source of multi-year predictability resides in the ocean. Here we show the first highly skilful long-term predictions of the commercially valuable Barents Sea cod stock. The 7-year predictions are based on the propagation of ocean temperature anomalies from the subpolar North Atlantic toward the Barents Sea, and the strong co-variability between these temperature anomalies and the cod stock. Retrospective predictions for the period 1957–2017 capture well multi-year to decadal variations in cod stock biomass, with cross-validated explained variance of over 60%. For lead times longer than one year the statistical long-term predictions show more skill than operational short-term predictions used in fisheries management and lagged persistence forecasts. Our results thus demonstrate the potential for ecosystem-based fisheries management, which could enable strategic planning on longer time scales. Future predictions show a gradual decline in the cod stock towards 2024.